The invention relates to a sheet-metal cage for a rolling-contact bearing and particularly to fastening cage segment ends together.
A sheet-metal cage, like all cages of rolling-contact bearings, guides the rolling bodies in their motion relative to the inner and outer bearing rings and holds the rolling bodies spaced at a distance from one another around the bearing. To optimize the production costs of a sheet-metal cage, it is recommended to produce the sheet-metal cage, for example, from punched-out material strips or segments which are bent in a circular shape and which have their segment ends connected.
Various connections for the ends of cage segments are shown in DE 8008271 U1. These connections include screws and other connecting parts. These are awkward to handle and are suitable for use only for solid cages. U-shaped clamps which hold the cage segments together are also described. The clamps must be fitted by hand, and they also have the problem that they have to absorb the entire centrifugal force of the cage segments. At high rotary speeds, these U-shaped holding clamps may separate from the cage.
The object of the invention is to provide a sheet-metal cage from individual cage segments and to secure the segments via cost-effective elements.
At least one and possibly two or more cage segments are joined by their opposite cage segment ends. There is a locking connection between the ends, e.g. a dovetail, which holds them circumferentially and a preferably plastic material locking element that passes through an opening through one of the closure parts at a segment end to integrally form the locking element.
An advantage of the invention is that the sheet-metal cage can be produced from sheet-metal strips and therefore circular waste blanks do not occur. After the sheet-metal cage or the sheet-metal cage segments have been punched out and bent into a circular shape, closure parts are interlocked in a positive manner at the joint between cage segment ends. A preferred connection is dovetailed.
The region around the closure parts is fixed by molding on of a plastic locking element, so that the two cage ends can no longer be displaced radially relative to one another. The locking element is molded on simultaneously from radially outside and inside the closure parts. The plastic is connected through an opening in the region of the closure parts to form one part.
The remaining gap in the region of the closure parts at the joint between the cage ends, which gap results from production tolerances, is likewise closed with the molded-on plastic. As a result, forces which act in the region of the cage in the circumferential direction are absorbed by the closure parts, interlocked in a positive manner, at the joint between the cage ends. The locking element therefore does not need to absorb these forces.